Net alignment of cellulose in the periclinal walls of the shoot apex surface cells inKalanchoe blossfeldiana. II. Flower development

摘要

Dome geometry and the pattern of net cellulose alignment in the periclinal walls of the surface cells ofKalanchoe blossfeldianawere examined during sequential stages of flower development. Floral apices of photoperiodically induced plants were dissected, stained, and observed under a dissecting microscope. The outermost cell layer(s) of the surface was surgically removed from the floral apex and viewed under a polarizing microscope. Correlations were found between the geometry of the dome, the pattern of cellulose in the surface cells, and the pattern of initiation of floral organs at the apex. Tangentially aligned cellulose was always observed around the periphery of the floral dome, whereas no net alignment of cellulose typically occurred in the centermost region. Circumferential reinforcement of cellulose was consistently observed at sites of incipient organ initiation, and the pattern of cellulose alignment on emerging primordia correlated with the type of organ development. No strict dependence was evident between the number and positioning of one whorl of floral ogans and that of the previous whorl.Key words: shoot, cellulose, flower, floral, organogenesis.